Search results for "Elastic"

Acoustic radiation force impulse point shear wave elastography of the liver and spleen in patients with Gaucher disease type 1: Correlations with cli…

2020

To evaluate the feasibility of acoustic radiation force impulse point shear wave elastography (ARFI-pSWE) of the liver and spleen in patients with Gaucher disease type 1 (GD1), and to assess correlations between organ stiffness and clinico-radiologic data, particularly the GD1 Severity Scoring System (GD-DS3).We retrospectively evaluated the results of ARFI-pSWE as measures of liver and spleen stiffness in 57 patients with GD1. The feasibility of the method was assessed. Correlations between elastography data and clinical data related to the metabolic syndrome, laboratory tests, and GD1-related clinico-radiologic data (bone marrow burden score, GD-DS3) were assessed.ARFI-pSWE provided relia…

Identification of circumferential regional heterogeneity of ascending thoracic aneurysmal aorta by biaxial mechanical testing

2019

Abstract Ascending thoracic aortic aneurysm (ATAA) in patients with bicuspid aortic valve (BAV) can present an asymmetrical aortic dilatation compared with patients with tricuspid aortic valve (TAV). This pattern of aneurysm dilatation led us to hypothesize that biomechanical differences likely induced by regional heterogeneity of material properties can underlie the observed asymmetric enlargement discrepancies between BAV ATAA and TAV ATAA. This study aimed to characterize the mechanical properties and associated aortic tissue stiffness changes along the circumferential direction of aortic rings collected from surgically-repaired patients with ATAA. Biaxial material testing was performed …

2018

The cutis laxa syndromes are multisystem disorders that share loose redundant inelastic and wrinkled skin as a common hallmark clinical feature. The underlying molecular defects are heterogeneous and 13 different genes have been involved until now, all of them being implicated in elastic fiber assembly. We provide here molecular and clinical characterization of three unrelated patients with a very rare phenotype associating cutis laxa, facial dysmorphism, severe growth retardation, hyperostotic skeletal dysplasia and intellectual disability. This disorder called Lenz-Majewski syndrome (LMS) is associated with gain of function mutations in PTDSS1, encoding an enzyme involved in phospholipid …

Resveratrol-Induced Temporal Variation in the Mechanical Properties of MCF-7 Breast Cancer Cells Investigated by Atomic Force Microscopy

2019

Atomic force microscopy (AFM) combined with fluorescence microscopy has been used to quantify cytomechanical modifications induced by resveratrol (at a fixed concentration of 50 &micro

Bifunctional Hydrogels Containing the Laminin Motif IKVAV Promote Neurogenesis

2017

Summary Engineering of biomaterials with specific biological properties has gained momentum as a means to control stem cell behavior. Here, we address the effect of bifunctionalized hydrogels comprising polylysine (PL) and a 19-mer peptide containing the laminin motif IKVAV (IKVAV) on embryonic and adult neuronal progenitor cells under different stiffness regimes. Neuronal differentiation of embryonic and adult neural progenitors was accelerated by adjusting the gel stiffness to 2 kPa and 20 kPa, respectively. While gels containing IKVAV or PL alone failed to support long-term cell adhesion, in bifunctional gels, IKVAV synergized with PL to promote differentiation and formation of focal adh…

Diagnostic accuracy of elastography and magnetic resonance imaging in patients with NAFLD: A systematic review and meta-analysis

2021

[Background and Aims] Vibration-controlled transient elastography (VCTE), point shear wave elastography (pSWE), 2-dimensional shear wave elastography (2DSWE), magnetic resonance elastography (MRE), and magnetic resonance imaging (MRI) have been proposed as non-invasive tests for patients with non-alcoholic fatty liver disease (NAFLD). This study evaluated their diagnostic accuracy for liver fibrosis and non-alcoholic steatohepatitis (NASH).

Prevalence and severity of nonalcoholic fatty liver disease by transient elastography: Genetic and metabolic risk factors in a general population.

2017

BACKGROUND & AIMS The worldwide spread of obesity is leading to a dramatic increase in the prevalence of nonalcoholic fatty liver disease (NAFLD) and its complications. We aimed to evaluate both prevalence and factors associated with NAFLD in a general population in a Mediterranean area. METHODS We considered 890 consecutive individuals included in the community-based ABCD (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340). Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were measured with FibroScan. Participants were genotyped for PNPLA3 rs738409 and TM6SF2 rs58542926 variants. RESULTS The prevalence of NAFLD in the cohort was 48%. NAFL…

The effects of pressure on the energy landscape of proteins

2018

AbstractProtein dynamics is characterized by fluctuations among different conformational substates, i.e. the different minima of their energy landscape. At temperatures above ~200 K, these fluctuations lead to a steep increase in the thermal dependence of all dynamical properties, phenomenon known as Protein Dynamical Transition. In spite of the intense studies, little is known about the effects of pressure on these processes, investigated mostly near room temperature. We studied by neutron scattering the dynamics of myoglobin in a wide temperature and pressure range. Our results show that high pressure reduces protein motions, but does not affect the onset temperature for the Protein Dynam…

Extracellular matrix composition defines an ultra-high-risk group of neuroblastoma within the high-risk patient cohort

2016

Background: Although survival for neuroblastoma patients has dramatically improved in recent years, a substantial number of children in the high-risk subgroup still die. Methods: We aimed to define a subgroup of ultra-high-risk patients from within the high-risk cohort. We used advanced morphometric approaches to quantify and characterise blood vessels, reticulin fibre networks, collagen type I bundles, elastic fibres and glycosaminoglycans in 102 high-risk neuroblastomas specimens. The Kaplan-Meier method was used to correlate the analysed elements with survival. Results: The organisation of blood vessels and reticulin fibres in neuroblastic tumours defined an ultra-high-risk patient subgr…

Large strain stimulation promotes extracellular matrix production and stiffness in an elastomeric scaffold model

2016

Mechanical conditioning of engineered tissue constructs is widely recognized as one of the most relevant methods to enhance tissue accretion and microstructure, leading to improved mechanical behaviors. The understanding of the underlying mechanisms remains rather limited, restricting the development of in silico models of these phenomena, and the translation of engineered tissues into clinical application. In the present study, we examined the role of large strip-biaxial strains (up to 50%) on ECM synthesis by vascular smooth muscle cells (VSMCs) micro-integrated into electrospun polyester urethane urea (PEUU) constructs over the course of 3 weeks. Experimental results indicated that VSMC …